<template>
  <div class="type-nav">
    <div class="container">
      <div class="nav-left" 
      @mouseleave="moveOut"
      @mouseenter="isShow=true"
      >
        <h2 class="all">全部商品分类</h2>
        <transition name='sort'>
          <div class="sort" @click='toSearch' v-show="isShow" >
          <div class="all-sort-list2">
            <div class="item"
                v-for="(c1,index) in categoryList"
                :class="{item_on:index===currentIndex}" 
                @mouseenter="moveIn(index)"
                :key="c1.categoryId">
              <h3>
                <!-- <a href="javascript:;" @click="$router.push({
                  name:'search',
                  query:{
                    category1Id:c1.categoryId,
                    categoryName:c1.categoryName
                  } -->
                <!-- })">{{ c1.categoryName }}</a> -->
                <a href="javascript:;" :data-category1Id="c1.categoryId" :data-categoryName="c1.categoryName">{{ c1.categoryName }}</a>
                <!-- <router-link :to="`/search?category1Id=${c1.categoryId}&categoryName=${c1.categoryName}`">{{ c1.categoryName }}</router-link> -->
              </h3>
              <div class="item-list clearfix">
                <div class="subitem">
                  <dl
                    class="fore"
                    v-for="c2 in c1.categoryChild"
                    :key="c2.categoryId"
                  >
                    <dt>
                      <a href="javascript:;" :data-category2Id="c2.categoryId" :data-categoryName="c2.categoryName">{{ c2.categoryName }}</a>
                      <!-- <a href="javascript:;" @click="$router.push(
                        {
                          name:'search',
                          query:{ 
                            category2Id:c2.categoryId,
                            categoryName:c2.categoryName
                          }
                        }
                      )">{{ c2.categoryName }}</a> -->
                      <!-- <router-link :to="`/search?category2Id=${c2.categoryId}&categoryName=${c2.categoryName}`">{{ c2.categoryName }}</router-link> -->
                    </dt>
                    <dd>
                      <!-- 三级分类标题 -->
                      <em v-for="c3 in c2.categoryChild" :key="c3.categoryId">
                        <!-- <a href="javascript:;" @click="$router.push({
                          name:'search',
                          query:{
                            category3Id:c3.categoryId,
                            categoryName:c3.categoryName
                          }
                        })">{{ c3.categoryName }}</a> -->
                        <a href="javascript:;" :data-category3Id='c3.categoryId' :data-categoryName='c3.categoryName'>{{ c3.categoryName }}</a>
                        <!-- <router-link :to="`/search?category2Id=${c3.categoryId}&categoryName=${c3.categoryName}`">{{c3.categoryName}}</router-link> -->
                      </em>
                    </dd>
                  </dl>
                </div>
              </div>
            </div>
          </div>
        </div>
        </transition>
      </div>
      <nav class="nav">
        <a href="javascript:;">服装城</a>
        <a href="javascript:;">美妆馆</a>
        <a href="javascript:;">尚品汇超市</a>
        <a href="javascript:;">全球购</a>
        <a href="javascript:;">闪购</a>
        <a href="javascript:;">团购</a>
        <a href="javascript:;">有趣</a>
        <a href="javascript:;">秒杀</a>
      </nav>
    </div>
  </div>
</template>

<script>
import {mapState } from "vuex";
import throttle from 'lodash/throttle'//导入lodash的优化 只用到了throttle可以只导入throttle

export default {
  name: "TypeNav",
  data(){
    return {
      currentIndex:-1,//参考值，当鼠标移入的下标和该值相等时 添加类名
      isShow:true
    }
   
  },
  mounted() {
    // this.getCategoryList();
    // if(this.$route.path!=='/home'){
    //   this.isShow=false
    // }
  },
  created(){
    if(this.$route.path!=='/home'){
      this.isShow=false
    }
  },
  methods: {
    // ...mapActions(["getCategoryList"]),
    //鼠标移入事件-------当鼠标快速移动时，下标打印不全。跟不上鼠标的移动速度
    //用到防抖和节流
    //防抖是给函数防抖，函数的多次执行，变成一次执行
    //节流是函数节流，函数的多次执行变成少次执行
    // mouseIn(index){
    //   this.currentIndex=index
    //   console.log(index);
    // }
    toSearch(e){
      if(e.target.nodeName!=='A'){
        return 
      }
      //自定义属性在dataset中是个对象，并且都是小写
      const {category1id,category2id,category3id,categoryname}=e.target.dataset;
      let query={};
      
      category1id ? query.category1Id=category1id :null;
      category2id ? query.category2Id=category2id :null;
      category3id ? query.category3Id=category3id :null
      query.categoryName=categoryname
      let location={
        name:'search',
        query
      }
      if(this.$route.params){
        location.params=this.$route.params
      }
      this.$router.push(location)
    },
    moveIn:throttle(function(index){
      this.currentIndex=index
      // console.log(index);
    }, 50,{ 'trailing': false }),//第三个参数表示节流函数在50ms之前执行，解决50m后鼠标移出item仍显示
    moveOut(){
    this.currentIndex=-1;
    if(this.$route.path!=='/home'){
      this.isShow=false
    }
  }
  },

  computed: {
    ...mapState({
      categoryList: (state) => state.home.categoryList,
    }),
  },
};
</script>

<style lang="less">
.type-nav {
  border-bottom: 2px solid #e1251b;

  .container {
    width: 1200px;
    margin: 0 auto;
    display: flex;
    position: relative;

    .all {
      width: 210px;
      height: 45px;
      background-color: #e1251b;
      line-height: 45px;
      text-align: center;
      color: #fff;
      font-size: 14px;
      font-weight: bold;
    }

    .nav {
      a {
        height: 45px;
        margin: 0 22px;
        line-height: 45px;
        font-size: 16px;
        color: #333;
      }
    }
    .sort {
      position: absolute;
      left: 0;
      top: 45px;
      width: 210px;
      height: 461px;
      position: absolute;
      background: orange;
      z-index: 999;

      .all-sort-list2 {
        .item {
          h3 {
            line-height: 30px;
            font-size: 14px;
            font-weight: 400;
            overflow: hidden;
            padding: 0 20px;
            margin: 0;

            a {
              color: #333;
            }
          }

          .item-list {
            display: none;
            position: absolute;
            width: 734px;
            min-height: 460px;
            background: #f7f7f7;
            left: 210px;
            border: 1px solid #ddd;
            top: 0;
            z-index: 9999 !important;

            .subitem {
              float: left;
              width: 650px;
              padding: 0 4px 0 8px;

              dl {
                border-top: 1px solid #eee;
                padding: 6px 0;
                overflow: hidden;
                zoom: 1;

                &.fore {
                  border-top: 0;
                }

                dt {
                  float: left;
                  width: 54px;
                  line-height: 22px;
                  text-align: right;
                  padding: 3px 6px 0 0;
                  font-weight: 700;
                }

                dd {
                  float: left;
                  width: 600px;
                  padding: 3px 0 0;
                  overflow: hidden;

                  em {
                    float: left;
                    height: 14px;
                    line-height: 14px;
                    padding: 0 8px;
                    margin-top: 5px;
                    border-left: 1px solid #ccc;
                  }
                }
              }
            }
          }
            &.item_on{
              background-color: skyblue;
              .item-list {
              display: block;
            }
            
          }
        }
      }
    }
     .sort-enter{
      height:0;
      opacity: 0;
    }
    .sort-enter-active{
      transition:all 1s
    }
    .sort-enter-to{
      height:461px;
      opacity: 1;
    }
  }
}
</style>
